CNN reports US satellites detected new imagery and radar emissions which indicate testing of components and missile control facilities.

Yonhap also reported an 1,800-ton North Korean submarine was spotted in the Sea of Japan which “may be collecting data” to prepare for a test-launch from the North’s largest submarine.

The test will likely be for an intercontinental ballistic missile (ICBM) or intermediate range missile test. North Korea successfully launched an ICBM on July 4 which had the range to hit Alaska or northern Australia.